<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <style type="text/css">
        div{
            width: 100px;
            height: 100px;
            animation-name: changeColor;
            animation-duration: 7s;
            animation-timing-function: linear;
            animation-iteration-count: infinite;
        }
        @keyframes changeColor {
            0%{background-color: red}
            15%{background-color: orange}
            30%{background-color: yellow}
            45%{background-color: green}
            60%{background-color: lightblue}
            75%{background-color: blue}
            100%{background-color: purple}
        }



    </style>
</head>
<body>
    <div>这是一个盒子</div>
</body>
</html>